It was Dannie Richmond who took her to that magical lady. Read it - lots of detail about that episode and several famous players, Mingus, Stan Getz, Herbie Mann etc.
The problem with Mingus was that there was no rehearsal before the gig, Mingus didn't explain much besides "play like Duke" which she had not studied by then, and simply shoved her off the piano bench to play some himself to show her the way. Consider she was still 17 yers old when she hit New York and was called by Mingus, who was given her number by Jerome Richardson, who lived a floor above her. Many guys called her when they needed a sub, but made the records with other pianists - their regular players. Surprisingly, she does not write about the only two record dates she actually made, with Pharoah Sanders, and George Braith. What she writes about Freddie Hubbard is not the kind of behaviour that puts him in a favorable light. Stan Getz is two-faced, takes much care on the one side and is totally occupied by his drug habits and sexual obsessions on the other. Herbie Mann pays well but but must keep everything under control and lets no one play more tha two chorusses. When she played some more, she almost got fired. She never tried to fit anyone's shoes but tried to play herself, everybody respected her for that, but the bandleaders, well most of them.